Hey, I'm new here...
I did a google search for a good, reliable, and fun-seeming community, so I dropped in here...

I'm in the U.S., <18, and am thinking about buying a USED Z3 beamer,... I'm working on choosing one: a Miata, s2000, or Z3 with similar specs (below)... The Z3, in my opinion, has the most up-to-date styling and looks the sexiest of all...

SPECS: Used Z3, Probably 1997 to 2000... With mileage going from 50k to a good 75k...

I've had varying experiences with many other cars, and a lot of them had to have MAJOR work done when they passed 50, 75, and 100k miles... Should I expect to do MAJOR work on the Z3 with the specs above, or any minor work? Please share your experiences, especially those of you who own beamers (not necesarrily Z3's, but it'd be nice) that follow the specs above...

I highly recommend the Z3. I found mine on Autotrader.com in April 2003. 1996 1.9L Z3 with 54K miles for $14995, what a deal!
Have had no major problems with her, now lovingly referred to as "Sweetness".
Upon purchase shet was well maintained but I had all the maintenance completed since I didn't know when it was last done: tune up, serpentine belt, oil service; radiator coolant; brake/ clutch fluid, transmission and rear end fluids all sucked out and new fresh installed (approx $400 parts & labor). Biggest improvement was much quicker brake pedal. Put new performance tires on her, Cooper Zeon (approx $500 installed) quite grippy, never slid in a corner and very good in the wet. Got a used BMW CD changer for the trunk, $200 installed.
I then had the Z3 Roadster (M version) shifter installed (approx $120 installed); this was like a new car. The shift throw was reduced by two-thirds, a lot of fun.
Ran through the winter, don't know where you live but buy snow tiers if you get snow.
Come spring of 2004 the shocks were shot, so I put Bilsten sport lowering shocks and H&R lowering spring on her (approx $800 parts), again she is like a new car. So low and sweet in the corners. The ragtop then needed replacement (8 years old), bottom stitching to window plastic dry rot. New top in northern VA area was only $800 installed.
Ran through the winter again.
Now spring of 2005 and with 104K miles I'm needing a new clutch. I believe the original is still in her, looking to get this done within a couple of weeks, approx $250 installed. Will need to get new tires for this year, another $500 ish, will probable get another set of Coopers. And am scheduling to have the stereo vastly improved with a new Pioneer head unit & additional speakers (plus the installed Infinity speakers) and a Crossfire amp to pump it up, approx $635.
Also have had to put in left and right fog lights, so low the rocks love them, $70 parts install yourself in 10 minutes. Oil changes every 3000-3500 miles with BMW synthetic oil, wiper blades, air filters.

As you can see nothing major that you would not expect with the mileage on the car. Engine is sweet and tight right up to the rev limiter @ 6500 rpm. Happy shopping -- Get the Z3